1. Field of the Invention
The present invention relates to a display apparatus suitable for a projector or the like, which employs a semiconductor light-emitting element as a light source, a display control method, and a program.
2. Description of the Related Art
Conventionally, there has been proposed a technique for providing a projection-type display apparatus which can realize a high contrast in a display screen. In this technique, two light modulation elements are provided on a projection optical path, and a product of the contrasts of these two light modulation elements is set as a synthetic contrast (for example, Jpn. Pat. Appin. KOKAI Publication No. 2009-265120).
There have been proposed various techniques including the technique of the above-described patent document, which aim at realizing a high contrast by adopting a complex configuration, for example, by using a diaphragm mechanism or a shutter mechanism, and two light modulation element mechanisms, on an optical path of a projection system.
In the meantime, in recent years, a projector device, which employs a semiconductor light-emitting element, such as an LED (light-emitting diode) or an LD (laser diode (semiconductor laser)), as a light source.
In the projector device using this kind of semiconductor light-emitting element as the light source, the element itself of the light source is temporarily turned off in synchronism with a video timing when the entire screen becomes all black during a projection operation. Thereby, the occurrence of so-called “black-floating” due to leak light, etc. in the display element is avoided, and a much higher contrast can be obtained.
However, when the element of the light source is turned off in synchronism with a video timing when the entire screen becomes all black, as described above, it is necessary to turn on the element of the light source once again at an exact timing of projecting, upon restoration of subsequent video, a color other than black on at least a part of the screen.
The present invention has been made in consideration of the above-described circumstances, and the object of the invention is to provide a display apparatus capable of displaying video with a properly high contrast, a display control method, and a program.